Resolve noexcept warnings on lambdas (#463)

When running with additional warnings enabled, a couple lambdas produce
a warning that they should be declared with noexcept. This addresses the
lambdas that had been identified while building.

Signed-off-by: Ben Magistro <[email protected]>

Author: bmagistro

src/g3log/active.hpp

@@ -48,7 +48,7 @@ namespace kjellkod {
 
    public:
       virtual ~Active() {
-         send([this] { done_ = true;});
+         send([this]() noexcept { done_ = true;});
          thd_.join();
       }
 

src/g3log/logworker.hpp

@@ -127,7 +127,7 @@ namespace g3 {
       /// This will clear/remove all the sinks. If a sink shared_ptr was retrieved via the sink
       /// handle then the sink will be removed internally but will live on in the client's instance
       void removeAllSinks() {
-         auto bg_clear_sink_call = [this] { _impl._sinks.clear(); };
+         auto bg_clear_sink_call = [this]() noexcept { _impl._sinks.clear(); };
          auto token_cleared = g3::spawn_task(bg_clear_sink_call, _impl._bg.get());
          token_cleared.wait();
       }